The present invention concerns the architecture of electronic computers, and in particular, an architecture in which the principal memory of the computer is distributed among many distinct processor units.
Since the development of the single integrated circuit ("chip") microprocessor in the early 1970s, the amount of memory on the microprocessor chip has been increasing. Part of this trend is driven by speed considerations. Data and instructions held in on-chip memory are accessed much faster than those which must be obtained from an off-chip memory device.
Some recently announced microprocessors have as much as 90% of their transistors devoted to memory. Nevertheless, there are economic and practical limits as to how much memory can be put on a single integrated circuit.